The construction of an Iranian MRI brain template

Background and Aim : The use of a common coordinate space is crucial for the analysis and reporting of neuroimaging experiments. From the time Talairach space was developed through dissection of a single brain to this day, researchers have tried to construct a high resolution standardized space compatible with every population under study. Recent studies have suggested that using a population specific target space can improve the results of spatial normalization of brain MR images. Hence, our objective is to develop an Iranian brain template and compare the result with the commonly used MNI space.Methods : In this study, we used the three-dimensional T1-weighted MRI data of 152 healthy young volunteers. After collecting data using a 64-channel head coil and a 3 Tesla Prisma MRI Scanner, we extracted the brain from each whole-head image. We built the Iranian brain template through a robust iterative algorithm. Basically, each brain extracted MR image was registered to an initial common space; then a tentative average was formed as the reference for the next iteration. This process continued until the difference between two consecutive templates reached and stayed at a minimum.Results : The aforementioned iterative procedure resulted in an Iranian standard template comparable with the commonly used MNI space. By overlaying these two templates we observed their differences in size and shape. We quantified this morphological difference by measuring four global brain features: length, width and height of the brain, as well as the AC-PC distance. The comparison of our results with the MNI-152 shows that the Iranian brain is smaller in average specially in length and height. In accordance with other similar studies, AC-PC distance is the most constant feature across templates.Conclusion : Our research shows that using the presented population-specific template can facilitate studies involving Iranian brain MR images, and improve their results.

کلیدواژه ها:

Standard Template ، MRI ، population-specific template